There is a fundamental gap in understanding better ways to engage patients with heart failure (HF) in symptom recognition, response, and communication with healthcare providers. Symptoms are the main driver of health- related outcomes for patients with HF and the primary driver of repeated hospital readmissions. Given that we are located in the Washington Heights neighborhood of New York City, a predominantly poor Latino community, we are uniquely positioned to address the health disparity in clinical outcomes for Latino patients with HF as well as others with HF using a mobile health (mHealth) application (app). The proposed long-term goal of this NIH K99/R00 application is to assist the candidate, Dr. Masterson Creber, in becoming an independent investigator with a program of research focusing on high quality, technology-based behavioral health interventions to improve outcomes and support patient-centered cardiovascular care for underserved patients with HF. The overall objective of the proposed project is to test the hypothesis that a novel app, mi.Symptoms can meaningfully alter patient-reported and clinical outcomes of patients with HF and lead to more successful symptom recognition, response and communication with healthcare providers. The central hypothesis is that empowering patients to take more control of their symptom experience using a technology-enabled point-of-care symptom reporting intervention (mi.Symptoms) can meaningfully alter symptom response behaviors the clinical outcomes of patients with HF. Guided by strong preliminary data, this hypothesis will be tested in the K99 phase of the study by pursing the following specific aims: 1) test the reliability and validity of mi.Symptoms (a novel mHealth app developed by Dr. Masterson Creber and a team from Columbia University School of Engineering), and 2) assess the usability of mi.Symptoms and examine relationships of its use with changes in patient-reported outcomes in a pilot feasibility study. In the R00 phase of the study, the specific aim is to: 3) examine the efficacy o mi.Symptoms on improving patient-reported and clinical outcomes as compared to usual care. The training plan for this K99/R00 Pathway to Independence Award will enable Dr. Masterson Creber to couple skills in biomedical informatics with clinical trial design and outcomes research. The approach has three innovative features: 1) it is grounded in the Theory of Situation Awareness in Dynamic Systems; 2) there is a close link between the theoretical model and unique functional elements of the mi.Symptoms web app (tailoring to patient preference by choosing an avatar, prompting to report symptoms, reinforcing symptom reporting with hedonic motivation, and decreasing barriers to facilitate communication with providers); and 3) it applies growth modeling to the analysis of multiple symptoms and outcomes over time. Findings from this study will provide insights into the development and testing of mi.Symptoms as well as many other mHealth apps. The research is significant because it addresses the important problem of patients with HF struggling to recognize and respond to their symptoms, and it addresses the health disparity in HF outcomes for Latino patients. To accomplish the aims of this proposed study, a robust mentorship team with internationally and nationally recognized experts has been built, including expertise in biomedical informatics with a focus on mHealth (Dr. Suzanne Bakken), cardiovascular behavioral health and clinical trial design (Dr. Karina Davidson), user-centered design (Dr. Steven Feiner), clinical heart failure management (Dr. Mathew Maurer), symptom monitoring (Dr. Kathleen Hickey), quantitative methodologies (Dr. Christopher Lee), and mHealth application development and testing (Dr. Cornelia Ruland). Since a spectrum of new knowledge and skills regarding biomedical informatics, computer science and user-interfaces, and behavioral health clinical trial design are required for the candidate's career as an independent scientist, this K99/R00 award will be extremely important and necessary to achieve the candidate's career objectives and expand symptom science and the science of self- management for vulnerable patients with chronic diseases.